NASHVILLE, TENN. – A diet that at least partially resembled the Mediterranean diet appeared able to forestall a significant number of strokes in results from a retrospective, epidemiologic study of more than 100,000 Californian women.
“Greater adherence to a Mediterranean diet pattern was associated with a 10%-18% reduced risk of total and ischemic stroke,” Dr. Ayesha Z. Sherzai said at the International Stroke Conference.
“Our finding emphasizes the importance of addressing diet as an important, modifiable risk factor for stroke,” said Dr. Sherzai, a neurologist at Columbia University in New York.
Although the findings Dr. Sherzai reported came entirely from women, “I believe that most of the reported data show that a Mediterranean diet protects against stroke in men as well as in women,” commented Dr. Ralph L. Sacco, professor and chairman of neurology at the University of Miami, in a video statement provided by the American Heart Association, which sponsored the conference.
Dr. Sherzai and her associates used data collected by the California Teachers Study, which enrolled and followed more than 130,000 women who worked as teachers or school administrators in the state during 1995. Their analysis focused on 104,268 of these women with complete data for the diet and stroke analysis and who remained California residents; data on incident ischemic and hemorrhagic strokes came from California’s hospital-discharge database for 1996-2011. During these years, the 104,268 women had 2,270 incident ischemic strokes and 895 incident hemorrhagic strokes.
The researchers obtained baseline diet data from a food frequency questionnaire each participant completed at enrollment in 1995. They rated each participant’s diet by its resemblance to the Mediterranean diet using a validated, 10-point scale first reported in 2003 (N. Engl. J. Med. 2003:348:2599-608). They then divided the women into five subgroups based on the extent to which their reported diet resembled a classic Mediterranean diet, with women who scored 0-2 least adherent (16% of the studied population) and women who scored 6-9 most adherent (24% of the population). Remaining women in the study included 18% with a score of 3, 21% who scored 4, and 20% who scored 5 (total equals 99% because of rounding). The Mediterranean diet is plant based, with high reliance on unrefined cereals, fruits, vegetables, and monounsaturated fats like olive oil with low consumption of meat, sugar/sweeteners, and saturated fat, Dr. Sherzai said.
In an analysis that adjusted for a variety of sociodemographic and clinical variables, women with a diet score of 6-9 has a statistically significant 17% reduced rate of all strokes, compared with women with a diet score of 0-2, Dr. Sherzai reported. Women with a diet score of 5 also had significantly fewer strokes, at a rate 12% below that of the women who scored 0-2.
For ischemic stroke only, women who scored 6-9 had 18% fewer strokes than women who scored 0-2, those who scored a 5 on their diet had 15% fewer strokes, and those whose diet scored a 4 had 16% fewer strokes than the comparator group, also statistically significant differences.
For the outcome of hemorrhagic stroke, none of the diet subgroups showed a statistically significant difference relative to the women who scored 0-2. But the trends went in the same direction, with women scoring 6-9 having 18% fewer strokes and women scoring a 5 having 12% fewer strokes.